Automatic fire-alarm transmission.



No. 777,067. PATENTED DEC. 13, 1904.

G. B BOWELL.

AUTOMATIC FIRE ALARM TRANSMISSION.

APPLICATION FILED JULY 7. 19oz. F0 2 SHEETS-BHEBT 1 2 gl ip 2 KL. 1 g 8 5a *0 QM'/ N I W n *1 k: as

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PATENTED DEC. 18, 1904.

. G. B. BOWELL. AUTOMATIC FIRE ALARM TRANSMISSION.

APPLICATION FILED JULY 7. 1902.

N0 MODEL.

INVENTOR. JSWJ W IT'NE S 3 ES.

W' I By his fittornqy W STATES Patented December 13, 1904:.

PATENT OFFICE.

ASSIGNOR TO THE PEARSON FIRE ALARM LONDON, ENGLAND.

SYSTEM, LIMITED, OF

AUTOMATIC FIRE-ALARM TRANSMISSION.

SPECIFICATION forming part of Letters Patent N 0. 777,067, dated December 13, 1904-. Application filed July 7, 1902. Serial No. 114,646 (No model.)

To t II/771N271 it may concern:

Be it known that I, Guonen BENNETT Bow- ELL, a subject of the King of Great Britain and Ireland, residing at Sinclair road, I/Vest Kensington Park, in the county of London, England, have invented certain new and useful Improvements in Automatic Fire-Alarm Transmission; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The object of this invention is to provide automatically by a single party-wire connecting a number of buildings with one central oflice' a means, first, for immediate communication of a fire-call from any such building in case of excessive heat acting upon any thermostat installed in that building; secondly, means for immediate communication of a call distinct from a lire-call in case of a connection in a building failing; thirdly, means for immediate communication from a building in case of a battery failing at that building, and, fourthly, means for disconnecting any battery which fails at a building and connecting the local circuits of such buildings to the main line in such a manner as to enable a temporary supply of'current to be furnished from the main line to continue the work normally performed by the local battery.

For the sake of clearness I will describe this present invention in its simplest form; but in doing so I do not bind myself to any particular form of apparatus in detail.

From the central oifice a single series circuit is provided which calls at each installation, this line being maintained normally as a constant-current circuit from a battery at the central ofiiice. Upon an interruption of this main line recording instruments in the oifice are made to operate in the usual manner. At each automatic transmitting-station I provide in series with this main line a code break- Wheel, an electromagnet, and a switch. The code-break is driven when released by the electromagnet by a train of clockwork in the usual manner, and a detent is provided, so

that during the rotation of the break-wheel the clockwork cannot become locked. These are the parts connected to the main-line circuit. The local circuit, which consists, usually, of a duplicate pair of wires throughout the building, each one having in series with it a number of thermostats or fuses, which would serve to cutout their circuits when acted upon by heat, is provided with a battery,

preferably of a typeadapted for closed-circuit working, and a relay, the contact of this relay being connected in shunt with the coils of the electromagnet in the main-line circuit and normall y keeping them out of action. The switch in the main-line circuit is operated by the train of clockwork when the break-wheel has been released, either by a lire-alarm, by a disconnection on the buildings wires, or by the exhaustion of the local battery, and when this switch is operated it cuts out the local battery and cuts into the main line for a supply of current to keep the installation working until the local battery has. been attended to. However, should the starting 01' the clockwork-train have been caused by a break in a building-wire if the two building-loops are in series another contact device driven by the clockwork bridges first the one loop and then the other, so that if the break is on one loop only the transmittefls break-wheel will only complete its first round; but should both loops be cut out the transmitter continues to turn in its call. If desirable, a local bell may be added at any or all of the installations and connected to be rung oil the local battery by means of a back contact on the local-circuit relay.

In the accompanying sheet of illustrative drawings, Figure 1 is a diagram showing the instrument and different circuits for one installation, several such installations being connected to a single party-line connecting a number of buildings to be protected to one central office; and Fig. 2 is a similar diagram showing a slight modification by which a trouble or primary call is also given when a fault occurs in the local circuit. Fig. 3 is a plan of a transmitter constructed according to this invention, showing the mechanism run down after having given a fire-call. Fig. 4: is a section taken through the transmitter breakwheel.

The break-wheel a is mounted on the axle b and .is driven by clockwork to make one revolution. It carries on its periphery the insulating-pieces 0, that determine the signals transmitted. The brush 2? bears on the breakwheel. The wheel is also provided with an insulated metal segment 27 that makes contact with a second brush 28 at the same time that the brush 6 is raised off the break-wheel. The detent (Z is mounted on the pivot f, and one arm is operated by the cam g in such manner that in the position shown the other arm holds up the armature h of the electromagnet E.

To put the parts of the transmitter in their normal working condition, the shaft Z) is rotated or wound up clockwise against the resistance of a spring until the pin 5 comes in contact with the other side of the arm 71. The cam g in this position will have released in its backward motion the detent (Z, the part in contact with and the projection i being raised out of the way by the projection of the cam. Normally a projectioni on the armature it prevents the arm Z of the escapement of the driving clockwork from vibrating, and consequently the break-wheel from rotating; but when the armature is attracted or held up the arm is free and the wheel rotates until stopped, as hereinafter described, or until it has completed its one revolution. An eccentric m actuates through the rod 71 the block 0, carrying contact-strips arranged between two sets of contact-springs with which they make contact.

0 is a relay-magnet whose armature when attracted makes an electric contact at p.

The transmitter T in the single party-circuit 1 2 is driven by clockwork and can make a complete revolution giving two rounds when released. The transmitter T is released when the electromagnet E is cut into the main circuit 1 2. The electromagnet E is connected into the main circuit, but is short-circuited by the switch- S when held in the position shown by the magnet 0, arranged in the local circuit, so that if the local circuit is broken the transmitter is released. The local circuit consists of the two parallel Wires 3 4, having inserted the fuses f and connected to the terminals 5 6 and 7 8, respectively. The contacts 11 and 16, also 12 and 17', and also 13 and 18 are connected together. The contactbars 19, 20, 21, and 22 are operated together by the cam m on the transmitter at the end of the first round.

9, 7, 4, 8, e, 13, 22, 14, 10, B. If a fault occurs in either of the wires 3 or 4, the current The main-line circuit is The local circuit is B,

will still pass through the other and hold the switch S. i

The wires 3 4 can be separately tested by breaking the contact at 23, 24c, 25, or 26. If, however, the battery fail or the fuses in the double wires 3 tare burned,the magneto looses the switch S. The current from the main line then passes through the magnet E, as follows: 1, E, 11, 21, 12, T, 2. hen the magnet E is cut into circuit, the armature Z6 is attracted to the position shown, and immediately the transmitter begins to rotate, and when the strips 0 are passing by the brushes the arm is held up, the detent (Z being in the position shown. Normally the armature h is down, preventing the arm Z from vibrating and bearing on-the reduced part of the cam. The armature 72, cannot thus be released by the breaking of the circuit in giving the signal. The magnet E releases the transmitter and it makes its first round, (half a revolution,) giving its signal at the central ofiice. At the end of the first round the cam m causes thecontact-bars 21. 22 to break their connection and the contact-bars 19 and 20 to make their connection. The current from the main line then passes as follows: 1, E, 16, 19, 15, 7, 4, 8, e, 18, 20, 17, T, 2. The resistance R is a shunt between 16 and 17 and takes a portion of the main current. The magnet e, if the wire 3 or 1 is intact, now attracts the switch S, and the magnet E is short-circuited and the transmitter T is again held up, the arm Z2, being released both from the attraction of the magnet and the detent (Z. The attendant at the central station having thus only received the single signal is notified that the local battery of this installation is spent. If, however, the fuses in the wires 3 4: are burned, the whole current passes through the resistance R, the switch S is not operated, the magnet E is not shortcircuited and still holds up the armature h, and the transmitter T makes its second round, giving the second or fire call at the central station.

In the modification shown in Fig. 2 the transmitter T is provided with an insulated piece 27, mounted on the transmitter-wheel, and at the half-revolution or first round of the transmitter making contact with the brush 28, and also makes contact with the transmitterbrush and raises it off the break-wheel.

The different constructions are similar to those already described, the contact alone being slightly difierent. In the normal position the main-line circuit is 1, S, T, 2. The local circuit is B, 29, 30, 31, 32, 3, 33, 34, 35,, 36, 37, l, 38, e, B. If the local circuit is broken from any cause, the magnet c releases the switch S, and the main circuit is then through the magnet E, which releases the transmitter. At the end of the first round the piece 27 makes contact with the brush 28 and the contact-bars 3O 35 break their contacts, and the contact-bars 39 40 make their contacts. Then the main circuit is as follows:

41, 40, ran 1 32,33,39 38, 28,2.

The magnet a then attracts the switch S and short-circuits the magnet E, so that the transmitter is arrested, provided that either the wire 3 or 4 is intact. A single round signal is thus received at the central station, and the attendant is thus notified that either the battery has failed or that there is a break in one of the wires 3 4:. If, however, the Wires 3 4 are both broken, the whole current passes by 1, 4:1, 40, a2, R, 28, 2, and the transmitter makes its second round or ire-call.

In order to insure that the transmitter shall not be stopped owing to the momentary breaking of the main circuit when the brush is passing over the usual insulating-pieces in the transmitter-wheel, the detent d, operated by the cam g on the transmitter-wheel, holds up the armature of the magnet E while the brushes are passing over the code portion of the wheel.

What I claim, and desire to secure by Letters Patent, is

1. In a fire-alarm installation the combination of a constant-current main circuit, a local circuit, a transmitter in the main circuit that when released interrupts the main circuit, a transmitter-controlling magnet in the main circuit, a switch in the main circuit, an electroinagnet in the local circuit that operates the main switch to shunt the main-circuit magnet when the local circuit is broken, and a local switch operated by the transmitter and adapted to place the local circuit in the main circuit.

2. In a fire-alarm installation the combination of a constant-current main circuit, a local circuit, a transmitter in the main circuit that when released interrupts the main circuit, a transmitter-controlling magnet in the main circuit, a switch in the main circuit, an electromagnet in the local circuit that operates the main switch to shunt the main-circuit magnet when the local circuit is broken, a local switch operated by the transmitter and adapted to place the local circuit in the main circuit, a detent, and a detent-cam on the transmitter that operates the detent when the transmitter is interrupting the main circuit so as to hold the transmitter unlocked.

3. In a lire-alarm installation, a transmitter consisting of a code break-wheel escape ment clockwork driving the code wheel, brushes bearing on the code-wheel, a magnet, a 1nagnet-armature that when released locks the escapement, and an eccentric on the breakwheel, an eccentric-strap, and a switch operated by the eccentric-strap.

4:. In a firealarm installation, a transmitter consisting of a code break-wheel escapement clockwork driving the code wheel, brushes bearing on the code-wheel, amagnet, a magnet-armature that when released locks the escapement, a cam on the break-wheel, a detent operated by the cam and adapted to hold the armature in its attracted position.

In testimony whereof I have aflixed my sig nature in presence of two witnesses.

GEORGE BENNETT BOWELL.

Witnesses:

ALBERT JONES, HERBERT C. BOLWELL. 

